Our compulsory voting is really "compulsory voting". It's "compulsory turn up to a polling station and get your name marked off". You can drop an empty ballot in the box, draw penises on it, or even just turn and walk out of the polling place.
Also, the OP underestimates the impact of the minor parties. While there are two major parties, one of them is a coalition between two parties (Liberals and the Nationals), and there's a significant block of smaller parties and independents that are big enough that when they vote together they can have a deciding vote on legislation.
Our compulsory voting is really "compulsory voting". It's "compulsory turn up to a polling station and get your name marked off". You can drop an empty ballot in the box, draw penises on it, or even just turn and walk out of the polling place.
Also, the OP underestimates the impact of the minor parties. While there are two major parties, one of them is a coalition between two parties (Liberals and the Nationals), and there's a significant block of smaller parties and independents that are big enough that when they vote together they can have a deciding vote on legislation.